Objectives

Understand the definitions used in hypothesis testing.

State the null and alternative hypotheses.

Find critical values for the z test.

State the five steps used in hypothesis testing.

Test means for large samples using the z test.

Test means for small samples using the t test.

Objectives (cont'd.)

Test proportions using the z test.

Test variances or standard deviations using the chi square test.

Test hypotheses using confidence intervals.

Explain the relationship between type I and type II errors and the power of a test.

Introduction

Statistical hypothesis testing is a decision-making process for evaluating claims about a population.

In hypothesis testing, the researcher must define the population under study, state the particular hypotheses that will be investigated, give the significance level, select a sample from the population, collect the data, perform the calculations required for the statistical test, and reach a conclusion.

Hypothesis Testing

Hypotheses concerning parameters such as means and proportions can be investigated.

The z test and the t test are used for hypothesis testing concerning means.

Methods to Test Hypotheses

The three methods used to test hypotheses are:

1. The traditional method.

2. The P-value method.

3. The confidence interval method.

Statement of a Hypothesis

A statistical hypothesis is a conjecture about a population parameter which may or may not be true.

There are two types of statistical hypotheses for each situation: the null hypothesis and the alternative hypothesis.

Hypotheses

The null hypothesis, symbolized by H0, is a statistical hypothesis that states that there is no difference between a parameter and a specific value, or that there is no difference between two parameters.

The alternative hypothesis, symbolized by H1, is a statistical hypothesis that states the existence of a difference between a parameter and a specific value, or states that there is a difference between...